But nothing good in life or medicine comes without a cost. With statins, the most common side effect is muscle aches. Some studies have estimated that as many as 20% of people on statins experience this symptom, which usually goes away when the medicine is stopped.

A more recent concern about statins is that they may increase the risk of developing type 2 diabetes mellitus. Some of this concern comes from a 2011 study published in the Journal of the American College of Cardiology (JACC) that examined data from 3 large clinical trials. These trials took people with cardiovascular disease and compared those who took high-dose Lipitor and those who either took a placebo or a low-dose statin. Overall, these studies showed that people who took high-dose Lipitor had a slightly increased absolute risk of developing diabetes. For instance, in one study people at the end of 5 years, 9% of people who took Lipitor developed diabetes versus 6% of those who took placebo. The people who had the higher risk of getting diabetes were either overweight, had high blood sugar, high blood pressure, or high high triglycerides. So these were people prone to get diabetes anyway. Lipitor may have further increased their glucose level into the diabetes range.

So what should we take away from this? Should we stop taking Lipitor and other statins out of fear that they will cause diabetes? The authors of the study say just the opposite. They write, “the risk of developing new-onset diabetes is greatly outweighed by the benefit in reducing cardiac death, heart attack, and stroke.” But this study does illustrate 3 important points:

1) Even wonder drugs like statins have potential drawbacks. Therefore, doctors and patients need to make sure that a patient really needs to be on a statin before starting it. The people who should be on statins are folks that have cardiovascular disease or are at increased risk for it.

2) People taking statins should have their blood sugar levels monitored on their routine blood tests.

3) Taking a statin to lower cholesterol isn’t a license to let yourself go. It’s still crucial to exercise regularly, eat well, and do the other stuff that makes up a healthy life.